First-year survival of great horned owls during a peak and decline of the snowshoe hare cycle

1996 ◽  
Vol 74 (6) ◽  
pp. 1092-1097 ◽  
Author(s):  
Christoph Rohner ◽  
D. Bruce Hunter
Keyword(s):  
Survival Rates ◽  
Bird Species ◽  
Population Cycle ◽  
First Year ◽  
Mortality Factors ◽  
Bubo Virginianus ◽  
Slow Development ◽  
Snowshoe Hares ◽  
First Year Of Life ◽  
The Cost

Most bird species have low survival rates in their first year of life, and the highest losses occur when juveniles become independent and disperse. Young great horned owls (Bubo virginianus), monitored by telemetry in the southwestern Yukon, Canada, survived well during the peak of the population cycle of snowshoe hares (Lepus americanus). Subsequently, juvenile survival collapsed parallel to the decline in hare densities. The proportion of starving owls did not increase, but there was a significant increase in mortalities involving parasitism and predation, probably as an interaction with food shortage. The mortality rates of juvenile great horned owls peaked before, not during, dispersal. We propose that extended parental care makes the postfledging stage safe during optimal conditions, but that the relatively slow development during this stage incurs the cost of increased susceptibility to disease and other mortality factors under environmental stress.

Factors Associated with Maternal Opinion of Infant Development—Clues to the Vulnerable Child?

PEDIATRICS ◽  
1982 ◽  
Vol 69 (5) ◽  
pp. 537-543
Author(s):  
Marie C. McCormick ◽  
Sam Shapiro ◽  
Barbara Starfield
Keyword(s):  
Birth Weight ◽  
Infant Development ◽  
Infant Health ◽  
Subsequent Development ◽  
First Year ◽  
Factors Associated ◽  
Slow Development ◽  
First Year Of Life ◽  
Relationship Of ◽  
The Relationship

A mother's expectations about the development of her infant have been found to be a strong determinant of child development, but little is known about the factors that may affect maternal assessment of development. In this study, the relationship of the mother's opinion of the development of her infant with several sociodemographic, antenatal, intrapartum, and infant health variables was examined for a large sample of 1-year-old infants for whom gross motor observations were also obtained at the time of the interview. Among those observed to be developing at an appropriate rate, 4.0% were perceived by their mothers as developing more slowly than the mothers considered normal; among infants developing more slowly, 28.6% were considered to be developing slowly by their mothers. In both groups, the major determinants of maternal opinion of slow development concerned the infant's health: low birth weight, congenital anomalies regardless of severity, hospitalization during the first year of life, and high ambulatory care use. These results indicate that maternal perception of infant development may not reflect the infant's level, but past or present illness, and raise questions about the influence of infant health on maternal-infant interactions and the effect of such interactions on subsequent development in the child.

The Cost of Prematurity: Hospital Charges at Birth and Frequency of Rehospitalizations and Acute Care Visits over the First Year of Life

2005 ◽  
Vol 105 (7) ◽  
pp. 56-64 ◽  
Author(s):  
Katherine D. Cuevas ◽  
Debra R. Silver ◽  
Dorothy Brooten ◽  
JoAnne M. Youngblut ◽  
Charles M. Bobo
Keyword(s):  
Acute Care ◽  
Hospital Charges ◽  
First Year ◽  
First Year Of Life ◽  
The Cost

scholarly journals Mothers' perceptions of their premature infant's communication: A description of two cases

2016 ◽  
Vol 21 ◽  
pp. 143-154
Author(s):  
Michelle Pascoe ◽  
Divya Bissessur ◽  
Pat Mayers
Keyword(s):  
At Risk ◽  
Premature Infants ◽  
Developmental Delays ◽  
Survival Rates ◽  
Physical Contact ◽  
First Year ◽  
Communication Development ◽  
Early Communication ◽  
Communication Difficulties ◽  
First Year Of Life

Background: Survival rates of premature infants have increased due to advances in medicine. Premature infants however, remain at risk for developmental delays including communication difficulties. The bonding and attachment experiences of premature infants and their parents are often challenged, further placing these infants at risk for communication difficulties. This study firstly aimed to explore mothers' perceptions of their premature infants' communication. The second aim was to explore the mothers' perceptions of their own role in the communication development of their infants.Methods: A descriptive, longitudinal study was conducted with two mother—infant dyads.Three visits took place in the first year of life. Subjective maternal reports were obtained through semi-structured interviews.Results: Differences in the two mothers' perceptions were noted. The mothers described helping their infants to communicate through physical contact and talking. Risk and protective factors for early communication development are discussed in relation to the findings.Conclusion: The findings support the need for a healthy mothereinfant relationship in the first few months of life. Health professionals should support premature infants and their families after discharge in order to help them interact with their infants and encourage attachment and bonding.

Aspects of survival in juvenile polar bears

1996 ◽  
Vol 74 (7) ◽  
pp. 1246-1252 ◽  
Author(s):  
Andrew E. Derocher ◽  
Ian Stirling
Keyword(s):  
Maternal Age ◽  
Polar Bear ◽  
Survival Rates ◽  
Mortality Factor ◽  
First Year ◽  
Hudson Bay ◽  
Maternal Condition ◽  
Sampling Regime ◽  
Fat Stores ◽  
First Year Of Life

We captured, weighed, tagged, and monitored polar bear (Ursus maritimus) cubs and yearlings in western Hudson Bay to examine survival rates and correlates with survival. Cub survival between spring and autumn increased with cub mass and maternal mass, but was not related to maternal age or maternal condition. Cub survival between spring and autumn varied annually between 39.0 and 100.0% and averaged 53.2%. Whole-litter loss between spring and autumn was 30.8%, and only 38.0% of the females did not lose any cubs. Survival of spring twins was similar regardless of size, but in triplet litters, survival between spring and autumn varied according to cub size. Minimum cub survival from one autumn to the next was 34.7% and was related to cub mass, maternal mass, and maternal condition. Cub survival during autumn was estimated at 83.0%. Survival during the first year of life was no more than 44.0% but we could not estimate an annual survival rate because of the sampling regime. Possibly because harvesting was the major mortality factor for yearlings (19.4% of the yearlings were removed from the population per year), no factors examined correlated with survival of yearlings. We found no sex-related differences in survival of cubs or yearlings in any period. Relationships between survival in polar bear cubs and their condition suggest that lack of food availability, sometimes due to low maternal fat stores for lactation, leads to starvation and may be the main cause of mortality.

scholarly journals Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river

2003 ◽  
Vol 60 (2) ◽  
pp. 356-370 ◽  
Author(s):  
J. Dumas ◽  
P. Prouzet
Keyword(s):  
Survival Rate ◽  
Survival Rates ◽  
Maximum Yield ◽  
First Year ◽  
South West ◽  
Salmon Population ◽  
Second Year ◽  
First Year Of Life ◽  
French River ◽  
Good Agreement

Abstract The abundance of the salmon population in the Nivelle River was assessed for 11 cohorts during all the stages of their life cycle, from eggs to spawners. A stochastic life history model was used to simulate the changes in numbers at each stage over several years and to evaluate the parameters of a Ricker-type Stock and Recruitment (S–R) relationship. Parameters necessary for managing the exploitation of the species were also estimated. The results indicated that an average deposition of 611 700 eggs (values varying in a proportion of 1 to 3, depending on the year) produced 4870 0+ parr in autumn (variation from 1 to 5.6); 71.8% of which belonged to the group of future 1-year old smolts. The age 1+ parr were eight times less numerous. Survival from egg to 0+ parr was on average 0.97%, but highly variable (varying from 1 to 15). It was density-dependent and followed Ricker S–R model with an optimum of 7800 parr for a survival rate of 3%. During their second year, the survival of 1+ parr reached 53.4% and varied little. The adult runs of complete cohorts amounted to 196 maiden salmon (range, 88 to 382) and previous spawners comprised only 0.9% of adults. Grilse (1 year in the sea) constituted the majority (88.7%). The overall survival rates from 0+ parr to adult returns (6.2% on average) varied three-fold. The majority was females among the grilse (56.2%) and 2-sea-year salmon (88.6%); all 3-sea-year adults were female. Eggs deposited per female averaged 4200, 8500 and 12 750 eggs in each age group, respectively. Simulations of population abundances at various life stages were in good agreement with the observed data. The S–R relationship revealed the low productivity and the vulnerability of this stock, mainly due to the low survival rate of the young during their first year of life. The maximum yield of 12.2% of recruits could be obtained from a deposition of 1 424 000 eggs, which is twice the present average level.

Improving production from September-born Merino lambs with a lupin grain supplement and phomopsis-resistant lupin stubbles

1993 ◽  
Vol 33 (6) ◽  
pp. 713 ◽  
Author(s):  
PW Morcombe ◽  
JG Allen
Keyword(s):  
Weight Loss ◽  
Liver Injury ◽  
Western Australia ◽  
First Year ◽  
Ewe Lamb ◽  
Grazing Sheep ◽  
Staple Strength ◽  
Good Productivity ◽  
First Year Of Life ◽  
The Cost

As a means of providing nutrition on dry pasture in the wheatbelt of Western Australia, supplements of lupin grain were fed to late-born Merino lambs and their dams before weaning onto lupin stubble. Each ewe-lamb pair consumed an average 19.5 kg lupin grain over the 46 days before weaning. This produced an extra 3.6 kg (P<0.01) liveweight gain by these lambs compared with their unsupplemented cohorts at weaning. The growth of the weaned lambs grazing phomopsis-resistant lupin stubbles was primarily influenced by the amount of residual lupin grain available to each sheep and liver injury caused by ingestion of phomopsins. In the first 69 days of stubble grazing, sheep stocked at 10ha gained 7.3 kg while those stocked at 20ka gained 2.1 kg (P<0.001). In the first 13 months of life, lambs supplemented with lupin grain before weaning grew more (P<0.05) clean wool by 0.17 kg than the unsupplemented lambs. However, the value of this extra wool would not have covered the cost of the lupin grain eaten. Wool staples produced by sheep grazed at 10/ha on lupin stubble were stronger (P<0.001) than those produced by sheep grazed at 20ha (24.4 v. 17.7 N/ktex). The position of greatest weakness in the staple coincided with weight loss prior to removal from the stubble. Singleton lambs born in September and weaned onto a phomopsis-resistant lupin stubble reached liveweights consistent with survival over the summer and good productivity in their first year of life. The effects of lupinosis and reductions in wool staple strength may have been avoided by monitoring liveweight change and taking the sheep off the stubbles when they were near peak liveweight.

Impact of Brook Trout (Salvelinus fontinalis) Predation on the Crayfish Orconectes virilis in Three Michigan Lakes

1979 ◽  
Vol 36 (10) ◽  
pp. 1191-1196 ◽  
Author(s):  
H. Gowing ◽  
W. T. Momot
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
First Year ◽  
Orconectes Virilis ◽  
Trout Population ◽  
Production Growth ◽  
First Year Of Life ◽  
The Cost ◽  
Slow Growing ◽  
Northern Michigan

The crayfish Orconectes virilis is a major component of the benthos of three small lakes in northern Michigan. These lakes contained stocked brook trout (Salvelinus fontinalis) populations (age-0 and age-I) at densities of 188, 411, and 1398 fish/ha. Crayfish were preyed upon by brook trout, but only during their first year of life. Two-year production of age-0 crayfish was approximately 94 kg in each lake; brook trout consumed only about 1–2% in lakes with lower density offish. Even with greater trout density and accompanying higher rate of exploitation (40%), there was no impact on recruitment of young crayfish because compensatory mortality of crayfish occurred in lakes with less trout predation. However, stocking trout at higher densities decreased trout growth and condition. While 2-yr production was highest (59 kg/ha) in the lake stocked at the highest density and lowest (17 kg/ha) in one stocked at the lowest density, the former was achieved at the cost of a very slow growing trout population. Most of the crayfish production is not utilized as trout food but enters the non-predatory pool of detrital organic matter. Key words: Orconectes virilis, brook trout, predation, production growth, mortality

scholarly journals Tetracycline Resistance in Escherichia coli and Persistence in the Infantile Colonic Microbiota

2006 ◽  
Vol 50 (1) ◽  
pp. 156-161 ◽  
Author(s):  
Nahid Karami ◽  
Forough Nowrouzian ◽  
Ingegerd Adlerberth ◽  
Agnes E. Wold
Keyword(s):  
Escherichia Coli ◽  
Ecological Impact ◽  
Tetracycline Resistance ◽  
Resistant Variety ◽  
First Year ◽  
Tetracycline Resistance Genes ◽  
Resistant Strains ◽  
First Year Of Life ◽  
The Cost ◽  
Population Counts

ABSTRACT The ecological impact of antibiotic resistance in the absence of selective pressure has been poorly studied. We assessed the carriage of tetracycline resistance genes, persistence in the microbiota, fecal population counts and virulence factor genes in 309 commensal, intestinal Escherichia coli strains obtained from 128 Swedish infants followed during the first year of life with regular quantitative fecal cultures. No infant was given tetracycline, but 25% received other antibiotics. Tetracycline resistance was identified in 12% of strains, all of which carried either tet(A) (49%) or tet(B) (51%) genes. Resistance to other antibiotics occurred in 50% of tet(A)-positive strains, 42% of tet(B)-positive strains and 13% of tetracycline-sensitive strains. However, colonization with tetracycline-resistant strains was unrelated to treatment with antibiotics. Strains that were tet(B)- or tet(A)-positive carried the genes for P fimbriae and aerobactin, respectively, more often than susceptible strains. Tetracycline-resistant and -susceptible strains were equally likely to persist among the intestinal microbiota for ≥3 weeks and had similar population numbers. However, when a resistant strain and a susceptible strain colonized a child simultaneously, the resistant variety showed lower counts (P = 0.03). In cases of long-term colonization by initially tetracycline-resistant E. coli strains, loss of tet genes occurred in 3 of 13 cases with variable effects on population counts. The results indicate that there is limited pressure against the carriage of tet genes in the infantile gut microbiota even in the absence of antibiotics. Resistant strains may possess colonization factors that balance the cost of producing resistance elements.

scholarly journals High philopatry rates of Yellow-legged Gulls in the southeastern part of the Bay of Biscay

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sergio Delgado ◽  
Alfredo Herrero ◽  
Asier Aldalur ◽  
Juan Arizaga
Keyword(s):  
Survival Rates ◽  
First Year ◽  
Bay Of Biscay ◽  
Older Individuals ◽  
Southeastern Part ◽  
High Dispersal ◽  
Colonial Seabirds ◽  
Larus Michahellis ◽  
Main Food Source ◽  
First Year Of Life

Abstract Background Philopatry rate is one of the main factors shaping population dynamics in colonial seabirds. Low rates of philopatry are linked to populations with high dispersal, while high rates are linked to populations with a very high spatial structure pattern (i.e., metapopulations). The Cantabrian Yellow-legged Gull (Larus michahellis) population is considered to be resident, with relatively low dispersal rates. Precise estimations of its philopatry rates are however still lacking. Here, we aimed to estimate philopatry rates in the main Yellow-legged Gull colonies of the province of Gipuzkoa, in the southeastern part of the Bay of Biscay. Methods We analysed 734 resightings, during the breeding season at the colonies of Getaria, Santa Clara and Ulia, relative to a total of 3245 individuals ringed at birth in these same colonies during a period of 13 years. These data were analysed using Multi-State Recapture models in MARK. Results After controlling survival and resighting probability, the average dispersal rate among colonies was 4% (± SD = 2%) when individuals are immature, decreasing to 1 ± 1%) for adult breeding gulls (i.e., philopatry rate was 99%). Annual survival rates were assessed to be 0.27 ± 0.02 for birds in their first year of life and 0.87 ± 0.01 for older individuals. The probability of observing immature birds in the colonies was 0.08 ± 0.01, as compared to 0.21 ± 0.02 in adult birds. Conclusions We obtained evidence of extremely high local philopatry rates, clearly within the upper limit found in gulls. A high philopatry favour a speciation in these species who are vulnerable to obtain the main food source (landfills and fishing discard) which are transforming under new ecological process.

scholarly journals Costi sanitari di un programma vaccinale: analisi di minimizzazione dei costi

2003 ◽  
Vol 4 (1) ◽  
pp. 25-32
Author(s):  
G. L. Colombo ◽  
A. Muzio ◽  
R. Giordani
Keyword(s):  
Cost Minimization ◽  
First Year ◽  
Liquid Formulation ◽  
Italian Market ◽  
Global Cost ◽  
Differential Costs ◽  
Mandatory Vaccination ◽  
First Year Of Life ◽  
The Cost ◽  
Cost Components

The global cost of a vaccination program is made up by many more cost components than the acquisition expense, although the former is the first cost usually taken into consideration when comparing two or more alternatives. The present article analyses the economical impact consequent to the use of two different hexavalent vaccine formulations (Hexavac, liquid ready for injection, and Infanrix Hexa, dry, to be re-hydrated) available on the Italian market for the mandatory vaccination of newborns during their first year of life. The cost minimization analysis was conducted considering only differential costs, i.e. those costs than can differ with the use of one of the two products, and not those common to the two competing products, such as acquisition cost (33 euro in average for both), the costs for the organization, the call of the infants to be vaccinated, etc.. The differences among the considered alternatives detected by this study regard the work for the preparation and administration of the vaccines, the quantity of special waste they produce and the incidence of serious febrile reactions leading to pharmacological treatment and physician consultation (body temperature > 40°C). The liquid formulation resulted more convenient in terms of cost for nurse work (0,63 euro saved per patient), waste disposal, and adverse reactions management. The robustness of these results was confirmed by sensitivity analysis and an estimate of the global saving for the Italian health system associated with the universal utilization of the liquid formulation is furnished.

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